Wide-expansion underreamer



Patented Sept. 25, w23.,

ROBERT E. SIMPSON, 0F TAFT, CALIFORNIA.

WIDE-EXPANSION 'UNDERREAMZEIR'.

Application led November 2, 1921.

To ZZ whom 't-may concern:

Be it known that I, ROBERT EDWARD SIMPSON, a citizen of the United States, residing at Taft, in the county of Kern and State of California, have invented a new and useful Tide-Expansion Underrea'mer, of which the following is a specification.v

This invention relates to cable underreamers adapted to ream out a hole below a well casing so as to make the hole of greater diameter than the casing shoe, and the collars which hold the sections of the casing together.

It is necessary with tools of this character that they shall be collapsed so that when they pass down through the casing the cut ting edges of the collapsed cutters will not cut into or foul with the casing, and there is provided between the base sections or upper ends of the cutters, and the cutting sections or lower ends of the cutters, an intermediate section which is constructed to form runners or riders that contact with the casing as the unde'rreamer is lowered, or withdrawn, therethrough, for the purpose of preventing the cutting edges of the cutters from contacting with the casing. Said cutters are mounted on the lower end of a stock and are normally held in expanded vposition by resilient means which will allow the cutters to yield and come into collapsed position when the expanded cutters below the shoe of the casing are drawn up to contact with said shoe, thus allowing the cutters to collapse and enter the casing from below.

In such toos as heretofore constructed, the riders on the cutters have been in the form of enlargements which become worn; and when so worn, they allow the cutting edges or corners of the cutters to foul the casing, with the result that sometimes they cut through the casing thus destroying the casing and causing large expense through the work of withdrawing the casing to replace the section thus damaged.

An object of this invention is to provide an underreamer that will avoid all the objections and difculties of the character referred to.

serial No. mais.

This invention relates to a novel construction of the underreamer throughout, and includes various parts and combinations of parts whereby the collapsing and expanding of the cutters is provided for by improved app`iances that are easily assembled and disassembled, and in which the working parts are not hidden by the stock.

An object of this invention is to provide an underreamer of strong and solid construction which will collapse ,to a Small diameter and form a tapered end for the tool `while "going down through the casing, and which will expand to a much greater diameter than with former tools of this class when snapped open under the shoe at the bottom of the casing or under the shoulder below which the underreaming is to be effected, or wherever the hole is to be reamed. Another object is to construct an underreamer of the character above outlined with few parts which are not likely to become displaced inside the hole and which will satisfactorily perform the wo-rk of pulling the cutters back into'place when the tool is being withdrawn through the casing shoe.

Another object of the invention is to provide a construction of cutter which will have a wider base to be acted upon by the stock of the underreamer; that is to say an object is to so construct the cutters and the stock, that the articulating surface between the same will be as great as possible at the eX- panded position so as to insure against likelihood of battering the tool at such surface.

A feature of the invention is that when the tool is collapsed, the riders are segments of a cylinder having a radius about that of the inside diameter of the casing.

In cable underreamers, that is to say, underreamers reciprocated in the hole, it is important that Vthe lateral extremities of the cutting edges shall project beyond the' produced periphery of the expanded cutters; and when such corners become worn the tool has to be dressed, that is to say, the edges have to be resharpened; and an object of this invention .is to so construct the cutters that the resharpening can be done with a minimum amount of time and labor.

A feature of the invention is that the two cutters are constructed to three diameters, namely the base section, the rider section and the cutting section; the base section and the cutting section at the top and bottom of the cutters respectively being cylindrical in form when in expanded position; and the combined riders being in cylindrical form in the collapsed position. This is effected in the process of manufacture by turning the base sections and the cutting sections while the two cutters are expanded to cutting position; the base section being turned to the diameter of the lower end of the stock and the cuttingl section turned to the diameter desired for the reamed hole; and by turning the rider section when the cutters are in collapsed position. The invention is broadly new, basic and pioneer in this respect.

Another object is to so construct an underreamer that replacing of worn parts 1s reduced to ay minimum.

A feature of the invention is the provision of tapered ribs on the tongue and tapered ways in the cutters to receive said tongue.

An object is to make provision whereby when the parts become worn the tool can be repaired by machining the stock back to take up the wea-r and theltool will then be practically as good as new without having to replace any parts.

Further objects, advantages and features of invention may appear from the accompanying drawings, the subjoined detail description and the appended claims. Y

The accompanying drawings illustrate the invention.

Figure 1 is an elevation showing the underreamer as it may appear at the bottom of a casing in ay well which has been underreamed to al point below the shoe of the casing. One of the cutters is shown in section and the expanded underreamer is shown in position to be withdrawn up through the shoe of the casing. A fragment of the jars which operate the underreamer is also shown.

Fig. 2 is an elevation in section on line m2, Fig. 1. The cutter-lifting rods and their actuating spring are shown intact. From the nature of the view the cutter shown is also shown intact.

Fig. 3 is a transverse section on line w3, Figs. 1 and 2.

Fig. 4 is a transverse section on line m4, Figs. 1 and 2.

Fig. 5 is a transverse section on line c5, F igs. 1 and 2.

Fig. 6 is a fragmental sectional elevation showing the underreamer collapsed as going up or down through the casing, a fragment of which is shown.

Fig. 6E is a section on line wsa, Fig. 6.

Fig. 7 is a fragmental perspective detail of the lower end of one of the cutter-holding` rods.

Fig. 8 is a perspective view of the stock detached, and dismantled.

Fig. 9 is a perspective view of one of the interchangeable cutters.

Fig. 10 is a perspective view of the other cutter from another angle.

Fig. 11 is an elevation of the inner face of one of the cutters.

Fig. l2 is a view looking directly at the base of one of the cutters.

Fig. 13 is a view of the lower end of the stock alone.

Fig. 14 is a perspective detail of the cuttersupporting block detached.

The underreamer comprises a stock having a body 1 that is provided at its upper end with the usual pin 2, the collar 3 and wrench square 4. Said body is provided with the spring chamber 5, the cutter holding rod guideways 6, 6 and the cutter holding tongue 7 having its outer or lateral edges enlarged to form the cutter retainers or ribs 8 having between them an upwardly reduced open space c, and also having the safety pin hole 9.

The cutters are alike and are constructed in part with reference to their expanded position as shown in Fig.v 1, andin part with reference to their contracted position asI shown in Fig. 6, and for convenience of description their parts will be referred to with reference to their expanded or working position shown in Fig. 1. Each of said cutters comprises the base 10, the cylinder sector 11y di extending from the base 10 a considerable distance toward the tip 12 between whichtip and said cylinder sector there is a taper 13; that is to say, said cylindersector and taper 13 appear in the collapsed tool and the cutters are constructed with a special view to providing the'extended parts 11 and 13 in the expanded tool, and making a cylindrical rider out of the cylinder sector 1I when the tool is collapsed.

Between the upper end of the base 1() and the upper end of the taper 13 the cutter is formed with two limbs 14 on opposite sides of a tapered way or tongueway which comprises an upwardly expanding slot 15 having a broad portion aand a narrow portieriv Lacasse l of the taper 13 to said abutment 17 where the broader portion a of the slot is open to the outside ofthe cutter, thus forming the two limbs 14, on the inner sides of which are formed the rails 18 that are engaged by the ribs forming the retainers 8 at the outer edges of the tongue.

The inner and outer surfaces of the ribs 8 and of the broad portion a of the tongueway, expand or taper; that isy to say, such surfaces equally expand inwardly and outwardly, respectively, in an upward direction and allow easier operation in collapsing and expanding the tool, and also permit the tongue to be machined back or retapered to take up wear and thus make a new bottom without replacing worn parts. y

-When assembled, the web 'of the tongue fits the narrow inside opening of the slot 15, and the ribs 19 of the tongue fit the broader portion of said slot.

On the inner face of .the cutter limbs 14, seats 20 for the heads 2l of supportingl rods 22 are provided. There are two semi-cylindrical seats for said rods in each cutter; and the upper ends of the cutters are recessed at 23 to accommodate the rods. 22. Said rods extend up through the holes which form the rod guides 6, 6 and also through the spring chamber 5 which is shown as being open from side to side of the body of the stock.

Said chamber opens to the outside of the stock and forms a guide-way for thecutter supporting block 24 which is fixed to both rods 22 by socketed set screws 25 and is supported by yielding means formed by a spring 26 that rests upon the floor'27 of the spring chamber 5, and operates to hold the base of the cutters against the lower end of the stock.

In assembling the underreamer, the spring is inserted into the chamber through the side ofthe stock and the block 24 is inserted above the spring and then the ends of the rods 22 are inserted into the holes 6 and run on up through' the spring 26 and *through the block and into the holes 6. The

cutters are applied to the rods so that the heads of the rods are in tle seats of the cutters and then are brought into position at the lower end of the stock as shown in Fig. 1. The set screws 25 are loose so that the block may be adjusted along the rods 22 toward the cutters. This may be done by any device mpable of compressing the spring 26.

Seats 28 for a toggle, not shown, are prolvided in the ends of the block so that by grappling the block with the toggle and apf plying pressure, the block may be drawn Atoward the cutters so as to give a decided tension to the spring; then the set screws 25 are tightened-on the rods and the tool is assembled;

The safety pin 29 is then inserted into the hole 9 and is thus brought into position to intercept the rod heads 21 so that the cutters canno-t be disengaged from the stock without first `removing said pin 29. Said safety pin hole 9 and the pin are threaded so as to avoid accidental displacement of the safety pin. The ends of the pin may be angular, but are preferably round as at 30, and project to be operated on by a wrench, not shown.

The cutters are providedv at the lower end of the limbs 14 with a retracting-shoulder 31 to engage the shoe of the casing to retract the cutters when the tool is drawn up to bring the cutters into and through the casing.

In practice when it is desired to lower the tool into the casing, the toggles will beapplied to move the block 24, and the block will be forced down to compress the spring until the cutters can be collapsed into the form shown in Fig. 6, and then said cutters are inserted into an open side or U-link, not shown. Then the toggles are removed and the tool is inserted into thel top of the casing a suliicient distance so that the cylinder sector 11 engages said casing, the U-link is then removed and the tool lowered through the casing. When the cutters escape from the shoe 32 at the lower end of the casing, the spring acting through the rods, draws the cutters back into the expanded position shown inFig. 1, whereupon the tool may be operated to underream the hole. When it is desired to withdraw the underreamer from .the hole it will be drawn up in the usual way yuntil the shoulders 31 engage the shoe, and

after the stock is drawn up further, the tongue. is partially withdrawn from the cutters, thus causing the spring to be compressed by the block 24 as it is held stationary relative to the casing by the engaged cutters.

When the spring is sufficiently compressed, shoulders 31 will slip from the shoe, and the tool may be withdrawn without any further interference of the tool with the casing.

In practical manufacture the cutters may be respectively made from pieces, not shown, of half round bar material of the radius desired for the intermediate, or inner section 13 of the collapsed reamer; that is to say, a little less than the radius ofthe inside of the casing beneath which the underreamer is to ream; then the upper end of the flat side of each piece is beveled at 33 to the angle required to give the proper spread to the vcutters when they are expanded to cutting position; then the pieces to form two cutters are fixed together in the expanded posltion and Ythe base section is turned to the diameter of the vstock and the cutting section is turned to -thediameter desired for the reamed hole. claim. i

1. An underreamer comprising a stock provided at its lower end with a downwardly tapering tongue; cutters having upwardly expanding runways in which the tongue engages; and yielding means to hold the cutters against the lower end of theV stock.

2. An 'underreamer comprising a stock having at its lower end a downwardly tapering tongue, the outer edges of which are enlarged; cutters having upwardly expanding ways to fit the tongue; and yielding means to hold the cutters on the tongue against the end of the Stock.

3. An underreamer comprising a stock having a body provided with a spring chamber with cutter holding rod guideways and with a. cutter holding tongue having cutterretainers and a safety pin hole; cutters, each of which comprises a tip and base, and a cylinder sector extending from the base a considerable distance toward the tip, there being a taper between the tip and the cylinder sector which appears in' the expanded tool; said cylinder sector being practically of cylindrical form when the tool is collapsed; each cutter having a tongueway extending from the approximate middle of the taper to the base and being formed above the upper end of the taper with two rails on opposite sides of the tongueway; said tongueway comprising a slot open on the inner face of the cutter parallel with the axis of the cutter and terminating on its outer surface at about the upper end of the cylinder sector to form an abutment against which 'the tongue engages when the cutters are in contracted position.

4.An kunderreamer comprising a stock terminating at its lower end in a tongue which is provided on each side with ribs having between them an upwardly reduced space; and cutters, the upper ends or bases of which are adapted to unitedly form a cylinder to fit the inside of a casing through which the stock may pass when the bits are in collapsed position;I said tongue being downwardly reduced and said cutters having seats to unitedly receive said tongue; and

said tongue and seats being adapted to snugly fit together when the bits are expanded. n

5. An underreamer comprising a stock" provided at its lower end with a tongue having downwardly reduced ribs; cutters having upwardly expanding ways in which the ribs engage, and yielding means to hold the cutters against the lower end of the stock. 6. An underreamer comprising a stock terminating at its lower end in a tongue which is provided on each of two opposite faces with downwardly reduced ribs having between them an upwardly reduced space; and cutters extending into the spaces and having tongueways in which the ribs engage. 7. An underreamer comprising a stock terminating at its lower end in a tongue which is provided on each of two opposite sides with ribs having between them an upwardly reduced space; cutters each of which comprises a tip, a base and a cylinder sector extending from the base a considerable distance toward the tip; the cutters extending into the spaces respectively and having a way in which the tongue engages, saidway having a narrow portion which is open to the inner surface of the cutter and which extends from the top of the base a considerable distance toward the tip, said way also having an upwardly expanding broad portion that terminates on its outer surface at the upper portion of the cylinder sector and that is open to both sides of the base, thereby forming limbs on opposite sides of said way and also forming an abutment against which the tongue engages when the cutters are in contracted position; and yielding means to hold the cutters against the lower end of the stock.

In testimony whereof, I have hereunto set my hand at Taft, California, this 25th day of October, 1921. i

ROBERT E. SIMPSON.

Witness JAMES `R. TowNsENn. 

